<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <div id="app">
      <a href="#/home">home</a>
      <a href="#/about">about</a>
      <div class="content">Default</div>
    </div>

    <script>
      const contentEl = document.querySelector(".content");
      window.addEventListener("hashchange", function () {
        switch (location.hash) {
          case "#/home":
            contentEl.innerHTML = "Home";
            break;
          case "#/about":
            contentEl.innerHTML = "About";
            break;
          default:
            contentEl.innerHTML = "Default";
            break;
        }
      });
    </script>
  </body>
</html>
